brody on eggs : they are dirty

i have a broody momma that i put 10 clean marin eggs under after a few days and her getting settled i could see she wasnt sitting on all the eggs so i checked her box and she hasnt been getting up to poop just pooping in the box and now the eggs that are left are nasty. she is still sitting and i have tried to pull out all the nasty shavings and replace with new anything else i can do they are scheduled to hatch on the 21st?? help i hate to lose this batch of marins

She may not be sitting on them, none of my broody hens have ever popped in their nests. You should candle them, you may not be able to see much due to marans eggs being so dark.
P.S. the only hens I found to poo in meeting boxes are the ones to lazy to get up on the roost. Good luck Michele